Water Heater Expansion Tank Overflow Leak

safesurfer · Oct 4, 2008

The overflow pipe coming off of the cold water tee line that my expansion tank is on for my water heater is leaking water (filling a bucket to the brim overnight.) I have not seen any evidence of water coming from the pressure relief valve at all. What might be causing this, a faulty expansion tank?

http://www.watts.com/pdf/1915356.pdf

Cass · Oct 4, 2008

???

Can you post a pic?

Sponsor · 2022-01-29T12:20:58-0800

Jimbo · Oct 4, 2008

Overflow, eh? Could it be a vacuum breaker? What are your static and dynamic pressures? Picture please!

hj · Oct 4, 2008

tank

The expansion tank does not have an "overflow" of any kind. So you either have some other problem, or a leaking connection.

safesurfer · Oct 4, 2008

Here's some pics.

No idea on the pressures I'm afraid, there are no pressure gauges on the system and to be honest I don't have a clue how to measure.

Additionally, I have tried flushing the tank through the drain valve to try and clean out the tank of any buildup - our water is quite hard (city main supply).

Thanks.

hj · Oct 4, 2008

pipe

Someone believes in the "belt and suspenders" way of installing things. That is a secondary pressure relief valve. It is not needed and may be out of adjustment.

Jimbo · Oct 4, 2008

Thanks for the pics.;
\
Your flue pipe is not pretty. The relief valve off the XT is probably 150 PSI ( check that ) and should not be relieving if the system pressure is OK. Check the static and dynamic pressure on your system. The discharge tube from the primary TP valve is also not proper at least in my area. It may pass code in your area.

Ladiesman271 · Oct 4, 2008

jimbo said:
The discharge tube from the primary TP valve is also not proper at least in my area. It may pass code in your area.

Looks the same as my water heater. Discharge tube within 12 inches of the floor (copper pipe in my case). No floor drain in my house (1958).

99k · Oct 4, 2008

I would take a screw driver and tap on the expansion tank. The bottom should sound dull, while the top of the tank should sound hollow and ring. If the whole take sounds dull, it may be waterlogged and may be allowing the system to build excessive PSI.

Jimbo · Oct 4, 2008

Ladiesman271 said:
Looks the same as my water heater. Discharge tube within 12 inches of the floor (copper pipe in my case). No floor drain in my house (1958).

Our code requires the discharge of the TP to terminate outside the dwelling, or "other approved location". The setup you have is not an "approved location".

hj · Oct 5, 2008

code

The relief valve terminating in a "safe" location is a requirement of ALL codes, but is sometimes one of the least enforced requirements, at least until it operates and floods the basement.

Gary Swart · Oct 5, 2008

This looks like a Rube Goldberg design! There are so many bad and/or questionable things in what you have, I would suggest a professional be contacted to come in and organize things properly.

safesurfer · Oct 6, 2008

Thanks guys.

The secondary pressure relief valve was only 75PSI. I tried replacing at first with a new valve with the same rating, but the leak continued. I decided to follow HJ's advice that it was not needed and just installed a plug -so far no problems. I've tapped the expansion tank and it doesn't seem to be filling to the top so I'm hopeful that this has taken care of the problem.

As far as code goes, this was a new house built in 2002 by an area developer so it would have been inspected and presumably met all local codes.

Water Heater Expansion Tank Overflow Leak

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